2. Percentage of correct answers

3. A BWhy is photosynthesis vital for all living organisms? 20.45What is the source of weight increase in plants during their growth? 19.31Why are plants called producers? 22.72Is it possible for animals to survive without plants in an ecosystem? 25.00What is the atmosphere, even though living organisms breath it continuously? 59.09Do plants carry out respiration all day or only during some periods of the day? 27.27How do plants benefit from the sun’s energy? 23.86Note: Total number of students asked was n=88.<br />Alternative conceptions<br />Students often exhibit strikingly similar misconception about photosynthesis. When the first question ‘Why is photosynthesis vital for all living organisms?’ was asked, only 18 students understand that plant both release oxygen and produce food through the process of photosynthesis, thus enabling the continuation of our lives. Others had incomplete and mistaken idea about photosynthesis.<br />The question ‘What is the source of weight increase in plants during their growth?’ tested students’ understanding of autotrophic feeding. Most students mentioned water and soil in their answers and seven mentioned carbon dioxide as source of the plants’ weight. Only 17 students know that the weight increase in plants comes from organic substances, produced by plants themselves.<br />The third question ‘Why plants are called producers?’ tested their knowledge about the role of photosynthesis in the ecosystem. There are 20 students believe that plant manufacture organic substance by photosynthesis, but about 23% of this group thought that plants are called producers because they produce oxygen. About half of students claimed that most plants produce fruit or vegetables, so they are called producers.<br />To test the students’ understanding about the concept of the food chain relationship between plants and animals, we asked them the fourth question ‘Is it possible for animals to survive without plants in an ecosystem?’ Most of them believed that animals need plants to survive. Only 22 students associated this with the process of photosynthesis. <br />The fifth question ‘What is the reason for keeping carbon dioxide at an optimum level in the atmosphere, even though living organisms breath it continuously?’ tested students knowledge about the relationship between carbon cycle and photosynthesis. Approximately 62 students have a clear understanding about the role of carbon dioxide in photosynthesis, but the remaining 36 students did not give accurate answers to this question.<br />The sixth question ‘Do plants carry out respiration all day or only during some periods of the day?’ tested students’ understanding of the plant respiration. About half of students claimed that plants undergo respiration only during the night. Only 24 students answered correctly that plants respire continuously during the day and night.<br />The last question ‘How do plants benefit from the sun’s energy?’ tested students’ knowledge of energy flow from the sun through to plants. About 24% of students correctly claimed that plants manufacture their own food via photosynthesis by using the sun’s energy. Others thought that plants have to use the sun’s energy for looking healthy while some believe that plants use the sun for keeping warm. <br />Bibliography<br />Ozay, Esra, Oztaz, Haydar. (2003). Secondary Students Interpretation of Photosynthesis and Plant Nutrition. Journal of Biological Education, v37 n2 p68-70.<br />